When clicking in a handle (in blue in the image below) that allows to rotate a shape, you don't always click in the center of it. My question is how do you deal with this (Δx, Δy) small vector (in red) from the click position (blue cross) to the handle center (blue dot), during the drag.
keep the same vector in the main coordinates system, it feels like the circle handle could rotate on his center. (lower blue cross in the rotated shape on the right)
keep the blue cross at the same position, but in the handle coordinate system, there it feels more natural to me. (second blue cross in the rotated shape)
- I could also simply center the handle on the mouse pointer as soon as I start dragging. But it will make a quick 'noncontinuous' move at t=0 if you see what I mean. Of course in practice the handle isn't larger than 20 pixels, which is small, but still..